Method for opening a watchcase



.Sept. 20, 1966 E. MORF 3,273,228

METHOD FOR OPEN ING A WATCHCASE Filed July 1, 1963 lit tor/w ys UnitedStates Patent 3,273,228 METHOD FOR OPENING A WATCHCASE Ernest Morf,Vaudijon, Colombier,

Neuchatel, Switzerland Filed July 1, 1963, Ser. No. 292,025 Claimspriority, application Switzerland, July 4, 1962, 8,044/ 62 5 Claims.(Cl. 29-177) This invention relates to watertight watchcases comprisinga cover member fitting a lodging of a watchcase body member to close thewatchcase tightly and in particular to the methods for opening such awatchcase.

The watchcases of the type more particularly considered here usuallycomprise a one-piece metallic section constituting both the case bandand the bottom and the cover member provided for closing the watchcaseconsists of the glass.

In order to open these watchcases the glass has thus to be removed.Since the latter has to ensure a tight closure of the watchcase, itsremoval, however, involves some difliculties.

In a first group of watchcases of the type above-mentioned, which areknown in the art, the glass comprises an outer flange extending aroundthe glass sleeve tightly fitting the corresponding lodging of themetallic watchcase section constituting the case band and the bottom.This glass can be removed by inserting a blade, such as for instance aknife blade, successively at different points under the glass flange andby lifting the glass progressively out of its lodging. These knownwatchcases have, however, the drawback that the peripheral glass flangesoonly becomes injured, because the glass used with watertight watchesis organic. It occurs indeed that the blade used to open the watchcasecauses the glass flange to become jagged.

To avoid this drawback independent metallic bezels have been used in thewatchcases of the type referred to above, said bezels comprising aninner rim extending under a glass shoulder. To remove the glass and openthe watchcase one proceeds as disclosed above. The blade is here,however, inserted under the metallic bezel and not under a glass flangeand the bezel distributes the lifting force exerted by the bladeregularly on a relatively large glass flange portion so that this glassflange is not submitted to exceedingly high stresses concentrated in onepoint and does therefore no longer risk to become jagged.

Since the metallic bezel of these known watchcases has no other functionas that to allow removing the glass without damaging the same, thewatchcases comprising such a bezel have to be made thicker thannecessary thus causing an unaesthetic effect. It is of course well knownto those skilled in the art that a watch movement having a relativelygreat thickness in its center portion can nevertheless be mounted in awatchcase so as to give the impression of a very flat watch if theperipheral part of the watchcase is made very thin. Now, the extra bezelabove-mentioned has the drawback to give a watch With a movement havinga predetermined thickness the appearance of being thicker than a watchwith a movement which is thicker than said predetermined thickness butthe casing of which does not comprise an extra bezel.

To avoid this drawback watchcases have been made with a glass comprisinga portion protruding from the metallic body member of the watchcase,said protruding glass portion being arranged so thatit may be gripped bymeans of a tool adapted for exerting not an axial but a radial pressureon the glass. A great variety of tools have even been put on sale toenable removing the glass in that way. One of these tools chieflycomprises a split ring which can be set around a cylindri- "ice calglass portion and then closed under strong pressure by means of tongs.Another known tool provided for the same purpose comprises a pluralityof jaws (15 to 20) each located on a lever mounted for rocking motionabout an axis which is perpendicular to that of the watchcase when thejaws of said tool surround the cylindrical surface of the glassprotruding from the watchcase metallic section. A movable core of saidtool enables causing all these levers to rock simultaneously, to gripthe glass between said jaws and to exert a strong radial pressurethereon.

If a glass arranged so that it can be removed upon exerting a radialpressure thereon permits to avoid the drawbacks involved by a glasswhich has to be removed by an axial force exerted thereon, itnevertheless involves further drawbacks. Thus, when a strengthening ringis located within the glass sleeve set in the lodging of the metallicwatchcase body for pressing this sleeve in a radial direction againstthe cylindrical wall of said lodging, in order to ensure a satisfactoryclosure of the watchcase, it may occur that the pressure exerted on theglass by a tool comprising a split ring solicits the strengthening ringbeyond its limit of elasticity, if said tool is not manipulated verycarefully. In such an event, the strengthening ring would be subjectedto a permanent deformation and would then be unable to press the glasssleeve satisfactorily against the wall of its lodging when the watchcasewould be closed again. With the tool comprising a plurality of jaws asindicated above the glass is exposed to the same danger. Moreover, ifsaid jaws are pressed too strongly against the glass, they producemarkings on the periphery of the latter.

Further tools are also known in the art for opening a watchcase bygripping a glass portion protruding from the metallic piece of thewatchcase. In this case the protruding glass portion is not made with anouter smooth cylindrical surface but either with a truncated conicalsurface which opens toward the outside of the watchcase or with acylindrical surface provided with an annular groove matching with acorresponding rib of the removing tool. These known glasses have,however, the drawback that they also increase the thickness of thewatchcase at its periphery. Moreover, they have still the drawback, thatthey do not have a standard shape and cannot therefore be replaced byevery watchmaker.

It is also known in the art to open a watchcase of the type referred toabove by applying a suction cup on to the glass and by producing then avacuum above the glass in order to increase its curvature and to closeits peripheral sleeve extending within the lodging of the metallicwatchcase piece. The pressure which can be exerted on the glass by thismethod cannot of course exceed one atmosphere. In order that so small apressure can produce a sufficient deformation of the glass, the lattermust have relatively large sizes and be made very thin. Moreover, thissuction method does not enable removing a glass provided with astrengthening ring. Finally, a glass which jumps out of its lodgingunder a pressure which does not exceed one atmosphere has still thedrawback that it is not safely fixed to the metallic piece of thewatchcase.

It is therefore an object of this invention to provide a method foropening a watchcase tightly closed by a cover member fitting a lodgingof a watchcase body member, which enables removing said cover memberwithout providing the same with means permitting to grip it, said covermember being secured to the watchcase body member in as strong a manneras may be required.

It is also an object of this invention to remove the cover membertightly closing a watchcase by increasing the watchcase inner pressureuntil the cover member jumps out of its lodging.

Still another object of the invention consists in pressing a limitedamount of air into a watchcase tightly closed by a cover member fittinga lodging of a watchcase body member, thereby producing a pressureincrease inside the watchcase, which is sufiicient in order to causesaid cover member to jump out of its lodging.

Further objects of the invention will still become apparent in thecourse of the following description.

The inner pressure of the watchcase can be increased from outside thesame for instance by means of a pump introducing air through an openingprovided through the Wall of the watchcase, said opening being usuallytightly closed by a removable stopper.

With a watch comprising a winding and hand setting stem in two pieces,one of the same extending within a passageway of the watchcase bodymemberand being removably connected by resilient means to the secondstem piece which extends within the movement, the passage through whichair can be introduced into the watchcase in order to increase the innerpressure thereof will of course be the stem passage. With such a watchthe method according to' the invention can be performed by removingfirst the outer stern part together with the crown, by connecting theoutlet of a pump to the stem passage and by increasing the innerwatchcase pressure by means of said pump.

The method according to the invention will now be illustrated by anexample disclosed with reference to the accompanying drawings.

In the drawings:

FIG. 1 is a part diametrical section of the watchcase which can beopened by the method according to the invention, and

FIG. 2 diagrammatically illustrates how the method according to theinvention can be carried out.

The movement 1 of the watch represented in FIG. 1 is located in awatchcase comprising a single metallic piece 2 which constitutes boththe case band and the bottom. This piece 2 is formed with a shoulder 3serving as support for the outside flange 4 of the move ment base-plate.Piece 2 is further provided in its upper portion with a lodging 5 whichserves to receive the glass 6. The latter closes the casing of the watchrepresented. For that purpose it comprises a cylindridical sleeve 7,which enters the lodging 5 and which is pressed against the cylindricalwall of this lodging by a strengthening ring 8. The casing of the watchrepresented is finally provided with a passageway 9 in which a pipe 10is tightly inserted. A first piece 11 of a winding and hand setting stemextends within passage 9 and pipe 10. A rusual winding crown (not shown)is fixed to the stem piece 1 1 and is provided with a Watertight gasketextending between a crown portion and pipe '10. The inner end of piece11 is split lengthwise and provided with a transversal bore so as toform two resilient jaws 12 and a lodging 13. A second stem piece extendswithin movement 1. This second stem piece comp-rises a flat portion 14protruding from the movement and ending in a thicker portion 15 normallyextending within bore 13. The two stem pieces are connected to eachother by portion 15 and bore 1 3 so that they are simultaneously bothdriven in rotation and shifted axially upon rotating the crown or movingthe same in axial direction from its winding postion into its handsetting position or vice versa.

The stem piece 11 is split over a sufficient length in order to formjaws I12 which have such an elasticity that both pieces of the stem canbe disconnected from each other upon exerting a strong axial thrust onthe'crown.

Stems of the type described are well known in the art. The couplingmeans of the two stern pieces are adjusted in such a manner that theforce which must be exerted on the crown in order to disconnect theouter stem piece from the inner one is a great multiple of that whichmust be exerted on the crown in order to cause the same to pass from itswinding position to its hand setting position. The

multiple usually chosen can be as great as ten without exposing the stemportions ensuring the coupling of the two stem pieces from any damagedue to a stress exceeding the limit of elasticity when the two sternpieces are disconnected from one another or connected again to eachother.

To open the casing of the watch described the crown is first removed byexerting an axial pull on the latter, which is strong enough in order tocause the jaws 12 to move away from one another and to leave the thickerportion 15. Pipe 10 is then-connected to the outlet of a pump or of anyother installation, apparatus or device arranged for increasing the airpressure within the cavity of the watchcase. This installation,apparatus or device is then actuated so as to increase the air pressurewithin the casing until the glass 6 jumps out of its lodging. A pressureof 3 to 4 atmospheres is usually sufficient in order to urge the glass 6out of its lodging.

A tool which can advantageously be used to perfor the method accordingto the invention is represented diagrammatically in FIG. 2. This toolconsists of a pump provided with a valve. It comprises a body member 16,a nozzle 17 and an actuating button 18 connected to a piston. Afterhaving removed the crown in the manner described above, pipe 10 isintroduced into nozzle 17 and button 18 is pressed sometimes until thepressure within the watchcase causes the glass 6 to jump out of itslodging. In this manner no violent air blow is produced within the watchmovement so that there is no risk to blow the lubricating oil from thebearings away or to injure the hair-spring at the moment at which theglass leaves its lodging. The air remaining in the pump cylinder of thetool described and which suddenly enters the watch movement under thepressure exerted thereon by button 18 when the watchcase opens is indeedvery small.

Instead of a tool comprising a pump of very small capacity one couldalso resort to a tool which can remove the glass in a single pumpingoperation. With such a tool the pump capacity should however be chosenin function of the volume of the watchcase cavity in order to avoid astrong air jet into the watch movement when the watchcase opens. A toolcomprising a pump, the cylinder of which has a volume substantiallyequal to about 25 cm. (cylinder diameter: 2 cm.; height: 8 cm.) givessatisfactory results.

The method according to the invention has the advantage to permitopening watchcases of any sizes. In order that this method can beperformed practically, the watch needs only be provided either with astem in two pieces of the type disclosed above or with a particularpassageway extending through the wall of the watchcase and being tightlyclosed by means of a removable stopper.

Another advantage of'the method according to the invention is due to thefact that this method permits manufacturing a watchcase having a veryfiat appearance. For this purpose it is sufficient to provide a lodging5, the depth of which is equal to that of the lodgings usually providedin the known casings with removable bottoms and arranged for receiving aglass carrying a strengthening ring. It will be observed that the glass6 has not to be arranged so as to offer a grip accessible from outsidethe watchcase. The upper glass surface can thus be made flush with theupper portion of the watchcase body member as with the known casingsprovided with a removable bottom.

Further modifications in performing the method disclosed above willstill appear obvious to those skilled in the art without departing fromthe spirit of the invention of sacrificing the advantages thereof.

I claim:

1. A method for opening a watchcase tightly closed by a cover memberfitting a lodging of a watchcase body member, comprising the steps ofconnecting the watchcase cavity to an air chamber having a predeterminedvolume, and urging the air from said chamber to said cavity, thepredetermined air volume of said chamber thereby producing inside thewatchcase a pressure increase strong enough to cause the cover memberthereof to jump out of its lodging.

2. A method for opening a watchcase tightly closed by a cover memberfitting a lodging of a watchcase body member and a winding and handsetting crown fitting a pipe tightly inserted in a passageway providedthrough the wall of the watchcase, comprising the steps of removing thecrown and pressing through the pipe associated therewith a limitedamount of air into the watchcase, thereby producing a pressure increasetherein which is sutficient in order to cause the cover member thereofto jump out of its lodging.

3. A method for opening a watchcase tightly closed by a cover memberfitting a lodging of a watchcase body member and by a winding and handsetting crown fitting a pipe tightly secured to the watchcase,comprising the steps of removing the crown, connecting the pipeassociated therewith to an air chamber having a predetermined volume,and pressing the air from said chamber through said pipe into thewatchcase, thereby producing a pressure increase therein strong enoughto cause the cover member thereof to jump out of its lodging.

4. A method according to claim 3, the cover member consisting of theglass.

5. A method for opening a watchcase tightly closed by a cover memberfitting a lodging of a'watchcase body member, comprising the steps ofconnecting the watchcase cavity to an air chamber and urging air fromsaid chamber into said cavity thereby producing inside the watchcase apressure increase strong enough to cause the cover member thereof tojump out of its lodging.

References Cited by the Examiner UNITED STATES PATENTS 961,375 6/1910Seabrook 29--427 1,883,662 10/1932 Fisher 29427 JOHN F. CAMPBELL,Primary Examiner.

T. H. EAGER, Examiner.

1. A METHOD FOR OPENING A WATCHCASE TIGHTLY CLOSED BY A COVER MEMBERFITTING A LODGING OF A WATCHCASE BODY MEMBER, COMPRISING THE STEPS OFCONNECTING THE WATCHCASE CAVITY TO AN AIR CHAMBER HAVING A PREDETERMINEDVOLUME, AND URGING THE AIR FROM SAID CHAMBER TO SAID CAVITY, THEPREDETERMINED AIR VOLUME OF SAID CHAMBER THEREBY PRODUCING INSIDE THEWATCHCASE A PRESSURE INCREASE STRONG ENOUGH TO CAUSE THE COVER MEMBERTHEREOF TO JUMP OUT OF ITS LODGING.